Rubber band stretching method



July 23, 1968 HOFFMAN ET AL 3,393,633

RUBBER BAND STRETCHING METHOD Original Filed Nov. 1, 1963 9 Sheets-Sheet1 July 23, 1968 H. R. HOFFMAN ET AL 3,393,633

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RUBBER BAND STRETCHING METHOD Original Filed Nov. 1, 1963 9 Sheets-Sheet4.

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9 Sheets-Sheet 8 July 23, 1968 H. R. HOFFMAN ET AL RUBBER BANDSTRETCHING METHOD Original Filed Nov.

July 23. 1968 H. R. HOFFMAN ET Al.

RUBBER BAND STRETCHING METHOD Original Filed Nov. 1, 1963 9 Sheets-Sheet9 INV TOR! 3 2. sifm W ,ftw

United States Patent 3,393,633 RUBBER BAND STRETCHING METHOD Henry R.Hoffman and Harry L. Sidenstick, Cincinnati, Ohio, assignors to KettTool C0,, Cincinnati, Ohio, a corporation of Ohio Original applicationNov. 1, 1963, Ser. No. 320,631, now Patent No. 3,186,333, dated June 1,1965. Divided and this application May 26, 1965, Ser. No. 458,878

5 Claims. (Cl. 1002) ABSTRACT OF THE DISCLOSURE A method of wrappingarticles with elastic bands f the type originally supplied as an ovaltube with slits forming separate bands, but an uncut area holding thebands in assembled relationship. In the first step, the endmost band ispushed inwardly toward the uncut area and is rotated approximately 90.In the next step, a series of fingers are inserted in the band to expandthe band to a size for receiving the articles. Simultaneously, the bandis torn from the remainder of the pack and is then pushed from thefingers to snap around the article being packaged.

This invention relates broadly to packaging and wrapping and isparticularly directed to a method of wrapping elastic bands, such asrubber bands, around an article. This application is a division of ourco-pending application for Rubber Band Stretching Apparatus, Ser. No.320,631, filed on Nov. 1, 1963, Patent No. 3,186,333.

The principal object of the present invention is to pro vide a method ofwrapping articles in which a plurality of rubber bands are stored, andeach rubber band is sequentially separated from the remainder. Theseparated band is stretched to form a large central opening and,fiinally, the separated band is released so that it snaps around anarticle which has been inserted within the band opening. One preferredform of band applying machine for carrying out the present method iseffective to perform these operations automatically in response toeither the mechanical actuation of a single member, such as a foot pedalor handle, or the actuation of an electrical switch. Thus, the presentmethod provides a ready means for wrapping rubber bands around articlesat a high rate of speed with a minimum of effort on the part of theoperator, or indeed no attention at all if the machine is installed aspart of an automatic conveyor and wrapper system.

The present method is particularly adapted to be practiced utilizing atubular rubber band assembly, although it is to be expressly understoodthat the machine is not limited to the specific rubber band assemblydescribed below. One preferred form of rubber band assembly which can beused in the present method comprises an elongated tubular aggregation ofadherent rubber bands. The tubular assembly is of oval configuration andis provided with a plurality of parallel, transverse cuts delineatingindividual rubber bands. The tube is not completely severed about itsperiphery, however, so that adjacent bands are held together by a thin,uncut strip extending parallel to the axis of the tube.

One preferred embodiment of a band applying machine for carrying out thepresent method comprises a curved, generally vertical feed chute inwhich one or more of these tubular rubber band assemblies is stored. Asupport element, or shelf, is spaced from the lower end of the chute andis positioned to engage at least a portion of the bottom surface of thelowermost band. The machine further includes a feeding mechanism forengaging the lowermost rubber band and feeding it to an expandermechanism.

"ice

The expander mechanism of this machine comprises four expander fingerswhich are initially disposed in close proximity to one another toreceive the rubber band which is forced over the fingers in anunstretched condition by the feeder mechanism. Means are provided forshifting the expander fingers until they occupy the corners of aquadrilateral. While the exact configuration of this quadrilateral mayvary depending on the shape of the article to be wrapped, we have foundthat one very satisfactory configuratiotn is that of a square, or atrapezoid approaching a square. When the expander fingers are shifted tothis latter position, the rubber band is stretched to form a largecentral opening. In practice, the operator manually inserts the articleto be wrapped into the central opening, or alternatively an article canbe automatically fed by a conveyor or the like.

The apparatus further includes a release mechanism effective todisengage the rubber band from the expander fingers allowing it to snapover the article being Wrapped. In the preferred embodiment of themachine, this release mechanism comprises a plurality of release fingerswhich are shifted in a plane transverse to the plane of the rubber bandnear the end of the operating cycle. These release fingers push the bandfrom the ends of the expander fingers and allow it to contract about thearticle being wrapped.

One of the principal advantages of the present rubber band applyingmethod is that bands can be wrapped around a series of articles at arapid rate, for example sixty a minute. Moreover, the wrapping can beaccomplished by an operator having little or no skill or dexterity. Thefeeding, stretching and release of the rubber bands are all accomplishedautomatically in timed succession in response to the mere depression ofa foot pedal, pull of a hand lever, press of a button or the like.

Still another advantage of the present invention is that the band can beplaced in any desired position along the length of the article. Theoperator can select this position at will by merely controlling thelength of the article inserted in the machine.

Still another object of the present invention is to provide a method forfeeding rubber bands from the chute to the expander fingers. In thepresent machine this is accomplished by orienting the expander fingersso that in their retracted or starting position they extend transverselyof the bottom of the chute. In their retracted position, these fingersare juxtaposed and are preferably oriented in a straight line extendingparallel to and beneath the lowermost rubber band of the tube. It is oneof the important concepts of the present invention that the lowermostband can be placed over the expander fingers by pushing against theperiphery of the band in a transverse direction toward the uncut stripso that the band pivots about the uncut strip into a plane parallel tothe tube axis. In this pivotal motion, the band passes over the fourexpander fingers and is firmly gripped by these fingers when they begintheir divergent movements.

It is another object of the present invention to provide a method forsequentially detaching each band from the remaining bands of the tubularassembly. In this regard, one important determination of the presentinvention is that the severing can be accomplished as a concomitant ofthe stretching, or expanding, operation without the need of any separatesevering mechanism. In other words, when the expander fingers stretchthe band they also are effective to pull the band from the next adjacentband of the tube.

These and other objects and advantages of the present invention will bemore readily apparent from the following detailed description of thedrawings illustrating a preferred embodiment of the present invention.

In the drawings:

FIGURE 1 is a perspective view showing a typical rolled articleencircled by a rubber band.

FIGURE 2. is a perspective view of a tubular stack of rubber bands foruse with the present apparatus.

FIGURE 3 is a diagrammatic front and side view of a stack of rubberbands showing the position in which the bands are supported above themovable expander fingers of the present machine at the beginning of anoperating cycle.

FIGURE 4 is a diagrammatic front and side view showing the manner inwhich the lowermost band is pivoted downwardly over the expander fingersby the feeder blade.

FIGURE 5 is a diagrammatic front and side view showing the manner inwhich a rubber band is initially expanded and torn from the stack byoutward movement of the expander fingers.

FIGURE 6 is a diagrammatic front and side view showing the paths ofmovement of the expander fingers as the band is stretched to anintermediate position.

FIGURE 7 is a semi-diagrammatic front and elevational view showing themanner in which the band is released from the expander fingers to snaparound the article.

FIGURE 8 is a front elevational view of one form of machine constructedin accordance with the principles of the present invention.

FIGURE 9 is a side elevational view of the machine shown in FIGURE 8.

FIGURE 10 is a cross sectional view taken along the line 10-10 of FIGURE9.

FIGURE 11 is a cross sectional view taken along the line 1111 of FIGURE10.

FIGURE 12 is a cross sectional view showing the band engaging feederblade in an advanced position.

FIGURE 13 is a front elevational view of the expanding mechanism in itsretracted or initial band receiving position.

FIGURE 14 is a front elevational view of the expanding mechanism showingthe expander arms in their extended position.

FIGURE 15 is a cross sectional view taken along the line 1515 of FIGURE9 showing the actuating linkage for shifting the expander arms,advancing the blade and pivoting the release fingers, the mechanismbeing shown in its starting position.

FIGURE 16 is an enlarged, partial cross sectional view similar to FIGURE15 showing the actuating mechanism at an early point in the cycle inwhich the feeder blade has advanced against the bands, but the expanderfingers have not yet been shifted.

FIGURE 17 is a view similar to FIGURE 15 showing the actuating mechanismat the extreme limit of its advance at the end of the operating cycle.

FIGURE 18 is a cross sectional view taken along the line 18-18 of FIGURE17.

FIGURE 19 is a front elevational view of a modified form of machinewhich is solenoid operated.

FIGURE 20 is a cross sectional view of the modified machine taken alongline 2020 of FIGURE 19.

The general principles of the present method and the operation of apreferred form of machine for carrying out the method can best beappreciated from a consideration of FIGURES l-7. In these figures,FIGURE 1 shows a typical article 10 over which has been snapped a rubberband 11 using the present machine. It is to be understood that article10 may be any type of article about which it is desired to place arubber band, for example a coiled newspaper, a wrapped commodity or thelike. It is also to be understood that resilient bands formed of plasticor the like can be used with the present machine in place of bandsformed of rubber. However, to provide a clearer understanding of thepresent inven- 4 tion, the machine will be described with respect to onparticular type of rubber band with which the machine is used mostadvantageously.

The rubber bands used in the present machine are initially supplied intubular form as is shown in FIG- URE 2. As there shown, the tube ofrubber bands 12 comprises an elongated aggregation of bands which areoval in shape and are substantially severed from one another. However,each adjacent band is joined to the next adjacent band by a thin uncutarea. This uncut area, indicated generally at 13 in FIGURE 2,constitutes a strip extending longitudinally of tube 12 parallel to thetube axis, and adjacent to the middle of one flat side of the ovalshaped tube.

As is shown in FIGURE 3, the tube of rubber bands 12 is inserted in thepresent machine so that the axis of the tube extends in a generallyvertical direction with the individual rubber bands 11 extendinggenerally horizontally. It is to be understood that the uncut stripportion 13 is disposed to the rear of the tubular assembly as viewed inthe front elevational view of FIGURE 3 and to the right as viewed in theside elevational view of FIGURE 3. The lowermost edge of the tube ofbands is supported above the fingers 1417 by means of a shelf member asis explained in detail below. It is to be understood that the article tobe wrapped with the band is not inserted in the machine until a latertime.

At the beginning of the cycle of operation, an actuating rod 18 (FIGURE8, now shown in FIGURES l7) is depressed in any suitable manner, such asby means of a hand lever, foot pedal, solenoid or the like. In themanner explained below, initial movement of this actuating rod causesfeeder blade 21 to be advanced into contact with the lowermost band 11aof the tube. Engagement of blade 21 with the lowermost band 11a causesthat band to become disengaged from the support shelf and to pivotdownwardly and rearwardly with the uncut portion 13 of the band servingas a hinge, or fulcrum point. As the band 11a is pivoted downwardly, itpasses over the four expanded fingers 14-17 which are disposed closelyadjacent to one another in a horizontal line beneath the lowermost band.

In the next portion of the operating cycle, further shifting movement ofthe actuating rod 18 causes the expander fingers 1417 to be shiftedapart to the intermediate position shown in FIGURE 5. As is shown inFIG- URE 5, the two outermost fingers 14 and 17 are pivoted downwardlyand outwardly with the major component of their movement being in ahorizontal direction. Simultaneously, the two innermost fingers 15 and16 are shifted downwardly and outwardly with the major component oftheir movement being downwardly. As these fingers are shifted, theystretch the rubber band and cause it to be torn or severed from the tube12. The rubber band is then entirely supported upon the four fingers14-17, while the tube 12 is held above the mechanism by the feed blade.

In the intermediate segment of the operating cycle, the four expanderfingers 14-17 are shifted further apart stretching the band 11a asubstantial amount and forming a large central opening. As shown inFIGURE 6, in this position the four expander fingers 14-17 are disposedat the corners of a trapezoid which approaches a rectangle. At thistime, the rubber band is stretched larger than the periphery of thearticle 10 about which it is to be snapped. The article can thus beinserted within the band at this point in the cycle. The present machinealso includes four release fingers for disengaging the band from theexpander fingers. As shown in FIGURE 6, the four release fingers 22-25,which are normally disposed adjacent to the rear ends of the expanderfingers, are advanced slightly toward the forward, or free, ends of theexpander fingers 14-17 before the expander fingers reach their mostadvanced position. In FIGURE 6, however, the release fingers 22-25 arestill spaced rearwardly of rubber band 110.

As actuating rod 18 is advanced at the end of the stroke, the outwardmovement of expander fingers 14-17 continues, and release fingers 2225continue to move forwardly engaging rubber band 11a and forcing thatband off of the free ends of expander fingers 14-17. The release fingers2225 are of a curved and angulated configuration, as is explained indetail below, so that the band does not remain in engagement with thesefingers but rather slips from engagement with them and snaps over thearticle in the manner shown in FIGURE 1. As the final step of theoperating cycle, the article 10 is removed from the machine and theactuating rod is released so that the mechanism is returned to itsstarting position ready for the commencement of another operating cycle.

The details of one suitable form of machine for stretching rubber bandsin the manner described above are shown in FIGURES 8-18. As there shown,the rubber band stretching machine 26 comprises a base member 27supporting an upright column 28, the column having mounted thereon ahousing 30. The housing supports and encloses all of the operatingmechanism of the device except for actuating rod 18 which is connectedas at 31 to a treadle lever 32. The rear end of this lever is pivotallymounted upon the base as at 33 while the front end of the lever carriesa foot pedal portion 34.

It is to be understood that when the lever is depressed, actuating rod18 is pulled downwardly and when lever 32 is released the actuating rodreturns upwardly to its original position under spring force. It is alsoto be understood that the foot pedal can be eliminated and the mechanismoperated by a hand lever if desired. Alternatively, the device can beelectrically operated in the man ner shown in FIGURES 19 and 20, or canbe powered by means of pneumatic or hydraulic cylinders.

As is shown in FIGURES 8 and 9, housing 30 is provided with an opening35 which extends completely through the housing and is adapted toreceive the article about which a rubber band is to be encircled. At thefront of the housing, opening 35 is surrounded by a guide tube 36 whileat the rear of the housing a shelf member 37 is mounted beneath theopening 35 to receive articles after they have been wrapped with arubber band.

A feed chute 38 is provided for storing and supporting one or more tubesof rubber bands 12 in a position in which the bands can be serially fedto the expander fingers. As is best shown in FIGURES 8, 9 and 10, feedchute 38 is of a generally oval cross section slightly larger than thecross section of the bands. The chute includes a front slot 40 toprovide access space to at least the lowermost band in the tube. Also,as is shown in FIGURE 9, feed tube 38 is preferably curved slightlytoward the rear of the machine.

This curvature provides a double function. In the first place, itreduces the downward pressure on the lowermost band to facilitateremoval of that band. Even more importantly, however, the curvature ofthe tube provides a positive guide for the operator to make certain thatthe tube of rubber bands is properly inserted in the machine.Specifically, for proper functioning of the present ma chine the tubes12 must be inserted with the uncut strip 13 disposed at the rear of themachine, i.e. against fiat rear wall 41 of the feed tube. The presentfeed tube, with its rearward bend, utilizes the property of the tube ofrubber bands that it will easily bend rearwardly along the uncut strip13, but cannot readily be bent forwardly from that strip.

Specifically, as viewed in FIGURE 2, if the righthand edge of the tube12 is held stationary, the forward edge 42 of the tube can be bentupwardly but cannot be bent downwardly without obviously disarrangingthe bands. Thus, an operator can readily place a tube of rubber bands infeed tube 38 with the uncut strip 13 along rear wall 41. However, whenthe operator attempts to force a tube of bands downwardly within thefeed tube after the bands have been improperly inserted with the uncutstrip 13 is registry with slot 40, the bands tend to jam within the tubeproviding an obvious indication that the rubber band tube has beenimproperly loaded.

The lowenmost end of feed chute 38 terminates at feeding station 43. Thedetails of feeding station 43 are best shown in FIGURES 10-12. As isthere shown, the lower end of feed chute 38 is mounted to a verticaldivider wall 49 disposed within the housing by means of brackets 44 and45 which are bolted or otherwise secured to the divider wall. Bracket 45also supports a U-shaped shelf member 46. This shelf member is spacedbelow the lower edge 47 of feed chute 38 by a distance slightly greaterthan the width of one rubber band. The shelf extends from the forwardedge of the chute only a fraction of the distance toward the rear wall41. As a result, a clearance space 48 is provided for enabling a rubberband to be pushed rearwardly over the shelf and pivoted downwardly overthe expander fingers 14-17 as is shown in FIG- URE 12. It is to beunderstood that the tube of rubber bands 12 slides freely within feedchute 38 so that the lowermost rubber band of the tube rests upon shelf46.

The feed mechanism for feeding the lowermost band onto the expanderfingers is indicated generally at 50. Specifically, as is shown inFIGURES l0-l2, this feed mechanism includes a yoke member 51 pivotallysecured at its upper end to flanges 52 provided by vertical wall 49. Theupper ends of the yoke are mounted upon an elongated pivot pin 53 whichextends between aligned openings formed in flanges 52 and the arms ofyoke 51. The lowermost end of the yoke carries rearwardly extendingfeeder blade 21. This blade is preferably formed of sheet steel, or thelike, and is secured to the lower edge of the yoke in any suitablemanner, such as by means of bolts 54. The feeder blade 21 is disposed topass between the lowermost end of feeder chute 38 and shelf member 46.In the preferred embodiment, the leading edge of the blade is preferablyof concave configuration so that the blade engages an appreciableportion of the periphery of the lowermost band resting on shelf 46.

Yoke 51 is spring urged toward an advanced, or feeding, position withthe blade extending beneath the feeder tube as is generally shown inFIGURE 12. Specifically, a spring 55 is coiled around pivot pin 53. Onearm 56 of the spring abuts the divider plate 49 while a second arm 57 ofthe spring engages an opening in an arm of the yoke. At the beginning ofthe operating cycle, the yoke is held in its retracted position with thefeed plate 21 spaced from the edge of chute 38 by means of a linkageincluding a rearwardly extending arm 58 formed on the upper end of theyoke member. This arm extends rearwardly through an opening formed inthe divider wall and, as is best shown in FIGURE 15, is disposed forengagement with a rocker lever 60.

Rocker lever 60 is an elongated lever having a flange 61 formed on thelower surface of one end of the lever and flanges 62 and 63 respectivelyformed on the upper and lower edges at the opposite end of the lever.Flange 63 is disposed for abutment with the upper surface of arm 58.Rocker lever 60 is pivotally mounted at its center portion upon a pivotpin 64 which is mounted upon a vertically slotted block 65, the block inturn being bolted or otherwise secured to the rear surface of dividerwall 49.

Flange 61 of rocker lever 60 is disposed for engagement with an abutmentscrew 66 which threadably engages a flange 67 formed on main pivot arm68. Main pivot arm 68 is pivotally mounted at one end on a pivot pin 70carried by divider wall 49. The opposite end of pivot arm 68 isconnected to actuating rod 18 in any suitable manner such as by means ofa hemispherical thrust bearing 71 in engagement with a mating bearingsurface 72 formed in the end of pivot arm 68. Eivot arm 68 is springurged upwardly to its retracted, or initial, position by means of a coilspring 73 having its lower end in engagement with the arm and its upperend carried by support member 74. When the main pivot arm 68 is in itsupper position as shown in FIGURE 15, abutment screw 66 engages flange61 and forces the pivot lever 60 to pivot in a clockwise direction asviewed in FIGURE 15. Thus, flange 63 forces arm 58 downwardly and yoke51 is pivoted outwardly away from the divider wall as is shown in FIGURE11. It is to be understood that main spring 73 produces a forcesubstantially in excess of that provided by coil spring 55.

However, when the pivot arm 68 is pivoted downwardly, i.e. in acounterclockwise direction as viewed in FIGURE 15, abutment screw 66 isshifted downwardly permitting rocker lever 60 to pivot in acounterclockwise direction as viewed in FIGURE 15. Arm 58 is thusallowed to pivot upwardly under the force of coil spring 55 and feederblade 21 is advanced beneath the end 47 of feed chute 38 under the forceof coil spring 55. As the blade advances, it engages the lowermost band11a in the chute and causes that band to pivot downwardly about theuncut strip 13. The band is thus forced over the four expander fingers14-17 disposed beneath the end 47 of feed chute 38 as is shown inFIGURES 11 and 12. It is to be understood that the feed blade 21advances beyond the position shown in FIGURE 12 to a position in whichit overlies the feed fingers and hence forces the lowermost band 11ainwardly an appreciable distance from the ends of the fingers. Inwardmovement of yoke 51 and feeder blade 21 is limited by the abutment offiange 62 with a stop screw 75 mounted upon a bracket carried by dividerwall 49. The blade in this position supports the tube of bands andprevents their being pulled downwardly when the lowermost band isseparated as explained below. It will be appreciated that the feed blade21 is advanced solely by spring force; so that in the case of a jam atthe feeding station, the feed mechanism is protected against damage.

In addition to the feed mechanism described above, the present bandapplying machine comprises an expander mechanism indicated generally at76. This expander mechanism comprises four expander arms 77-80 whichrespectively carry at their outer free ends expander fingers 1417. Thesefingers extend forwardly from the arms 77-80.

As is best shown in FIGURES 13 and 14, each of the upper expander arms77 and 80 is pivotally jointed to a reciprocating pin 81. This pin, asis explained below, is shifted vertically within a slot 82 formed inblock and divider wall 49. Each of the upper arms 77 and is also joinedto a link 83, 84. These links are pivotally mounted at their upper endsto pivot pins 85 and 86 carried by divider wall 49. The lower ends oflinks 83 and 84 are pivotally connected to arms 77 and 80 adjacent tothe expander fingers 14 and 17 respectively.

Each of the lower arms 78 and 79 comprises an elongated segment 137, 138and a short segment 87, 88 angulated slightly relative to the elongatedsegment. Each of the lower arms is mounted upon a pivot pin 90, 91 atthe juncture of the short and long segments of the arm. The pivot pins90 and 91 are carried by divider plate 49. Arms 78 and 79 are actuatedby means of cross links 92 and 93. Link 92 is connected to the free endof short segment 87 and to the mid section of the remote upper arm 80.Similarly, link 93 is connected to the free end of short segment 88 andto the mid section of the remote upper link 77.

As explained above, expander fingers 1417 are mounted at the free endsof arms 77-88 respectively. These expander fingers are preferablycylindrical in configuration and, as shown in FIGURE 11, extendforwardly to substantially the plane of the feed chute 38. The arms areshifted through a lost motion mechanism including a box-like sectionincluding an elongated opening 89 formed on the mid portion of mainpivot arm 68. This elongated opening receives reciprocating pin 81. Thispin extends rearwardly from arms 77 and 80 through slot 82 in dividerwall 49 and slotted block 65. The pin is mounted in a slide block 94which slides vertically in an undercut vertical groove formed in block65. Pin 81 is threaded at its rearward end and is bolted to verticallyreciproeating wing plate 99. Vfing plate 99 also carries a bolt whichpasses forwardly from the wing plate and carries a camming sleeve 169disposed within opening 89, the forward end of bolt 100 engaging slideblock 94. It is to be understood that pin 81 also passes through cammingsleeve 169.

As is shown in FIGURE 15, slide block 94 is disposed to pass between aroller 95 and divider plate 49 when the actuating rod 18 and pivot arm68 are in their upper or initial position. Roller 95 is mounted on a pin96 carried by a bracket 97, the bracket in turn being mounted upondivider wall 49. This roller exerts a sufficient frictional forceagainst slide block 94 to frictionally retain that block in its elevatedposition during the initial lost motion movement of the pivot arm 68,i.e. until that arm is shifted downwardly a sufiicient distance so thatthe upper edge 98 of elongated slot 89 engages the cam block 169 carriedby bolt 100. Thus, when actuating rod 18 is initially depressed, mainpivot arm 68 pivots downwardly from the position shown in FIGURE 15 tothe position shown in FIGURE 16. During this time, the feed plate 21 ispivoted rearwardly under the force of coil spring 55 to pivot rubberband 11a downwardly over the four expander fingers 14-17. During thisinitial movement of the pivot arm, slide block 94 remains in itselevated position due to the frictional force exerted by roller 95.However, after arm 68 has pivoted a sufficient distance to bring uppersurface 98 into contact with cam sleeve 169, slide block 94 is shifteddownwardly carrying with it pin 81. As pin 81 shifts downwardly from theretracted position shown in FIGURE 13, upper expander arms 77 and 80 arecaused to pivot outwardly about their points of connection to links 83and 84 at the same time, links 83 and 84 pivot outwardly about pins 85and 86. At the same time, lower arms 78 and 79 pivot downwardly andoutwardly about pins 90 and 91. By the time the expander arms reach thelimits of their movement, the rubber band is stretched by expanderfingers 1417 into a large trapezoid as shown in FIGURE 14. By this time,the article has been inserted into opening 35 and is thus positioned toreceive the band when the band is disengaged from the expander fingers.

The function of releasing the band from the expander fingers isperformed by a release mechanism indicated generally at 101. Thismechanism is best shown in FIG- URES l4-18. Specifically, the releasemechanism includes two vertical side shafts 102 and 103' extendinggenerally along each side of opening 35. In the specific embodimentshown, these shafts are not disposed along precisely vertical lines, butrather are angulated slightly inwardly at the bottom.

Each of the vertical shafts 102 and 103 respectively carries an upperrelease finger 22 and 23- and a lower release finger 24 and 25. Thesefingers are secured to the shafts in any suitable manner, such as bymeans of set screws 104 which engage nuts 105 surrounding the shaft andextend through the end of a U-shaped channel section 106 formed at thelower end of the release fingers.

Each of the vertical shafts 102 and 103 is pivotally mounted in flanges107-110 carried by divider wall 49 and extend forwardly therefrom ingenerally horizontal planes. A thrust bearing 111 and 112 is mountedupon each of the shafts beneath the lowermost flanges 109 and 110. Athrust and actuating arm assembly 113 and 114 is mounted at theuppermost end of each of the rods. As is best shown in FIGURE 14, eachof the thrust and actuating assemblies comprises a washer 115surrounding the shaft in engagement with one of the upper flanges,

such as flange 107. A U-shaped arm member 116 is mounted above thewasher and is secured to the shaft by means of a set screw 117 whichpasses through the arm and through a threaded nut 118 and engagestheupper end of the shaft. Each of the arms 116 passes rearwardly throughan opening formed in vertical divider plate 49.

Each of the shafts 102 and 103 is spring urged to a. retracted positionin which the fingers are disposed in a vertical plane parallel todivider plate 49 as is shown in FIGURE 10. This is accomplished by meansof coil spring 120 and 121. Each of the coil springs is wrapped aroundone of the shafts 102, 103 and includes an arm 122, 123 in abutment withdivider wall 49 and a second arm in engagement with actuating armassembly 113.

Pivotal movement of shafts 102 and 103- in their retracted direction islimited, as is best shown in FIGURES 13 and 15, by the abutment of arms116 with angle arms 124 and 125 pivot-ally mounted upon the rear surfaceof divider wall 49 as at 126 and 127. Outward pivotal movement of theangle arms is limited by stops 128 and 129 bolted to the rear surface ofthe divider wall.

The angle arms 124 and 125 also constitute part of the mechanism forshifting the release fingers outwardly at the end of the operating cycleto force the rubber band from the ends of the expander fingers 14-17.Specifically, as is shown in FIGURE 15, each of the angle arms 124, 125includes a flange 130 and 139 formed on the arm not in engagement witharms 116 connected to the vertical shafts 102 and 103. In the retractedposition of the release fingers, flanges 130 and 139 extend in agenerally horizontal direction and are disposed for engagement withdepending abutment screws 131 and 132 threaded into the ends of wingplate 99. These abutment screws are of a length such that they engageflanges 130 and 139 only after the expander fingers have been shifted tosubstantially their greatest opening.

At this point, actuator rod 18 and main pivot arm 68 have been shifteddownwardly a major portion of their stroke. Further downward movement ofactuator rod 18 and pivot arm 68 forces wing plate 99 downwardly to apoint where abutment screws 131 and 132 abut flanges 130 and 139 ofangle arms 124 and 125. Additional downward movement of the pivot arm,wing plate and abutment screws cause angle members 124 and 125 to bepivoted in such a manner that their upright portions are shiftedinwardly toward block 65. The upper ends of these arms in turn causearms 116 and shafts 102 and 103 to pivot in such a manner that therelease fingers swing outwardly. It is to be understood that in theirinitial position the release fingers are disposed rearwardly of therubber band carried by the expander fingers.

In the preferred embodiment, at the time that the release fingers startto pivot outwardly, the lower expander fingers 15 and 16 have passedjust below the tips 133 and 134 of release fingers 24 and 25. At thesame time, upper expander fingers 14 and 17 have reached a position justover the tips 135 and 36 of upper release fingers 22 and 23. As is bestshown in FIGURE 14, the lower release fingers 24 and 25 are curvedupwardly with the lower edges of these release fingers conforminggenerally to the arcs of movement of expander fingers 15 and 16.Similarly, the upper surface of upper release fingers 22 and 23 followsgenerally the arcs of movement of upper expander fingers 14 and 17.

During the final downward movments of the actuating rod 18 and mainpivot arm 68, the expander fingers continue to shift apart, as is shownin FIGURE 14, and simultaneously the release fingers are pivotedoutwardly. The release fingers thus force the band on the expanderfingers off the free ends of the expander fingers and cause it to snaparound the article disposed within opening 35.

When the actuating rod 18 is freed to move upwardly by the removal ofpressure from foot pedal 34, spring 73 pulls pivot arm 68 upwardly. Thewing block 99 is initially shifted upwardly by the spring action of coilsprings and 121. These springs pivot shafts 102 and 103 so as to returnthe release fingers to their retracted postion. As shafts 102 and 103pivot, fingers 116 cause angle members 124 and 125 to pivot. The flangesand 139 on these members force stop screws 131 and 132 and wing block 99upwardly. After angle members 124 and 125 engage stops 128 and 129,movement of the wing block is temporarily halted. Pivot pin 81, whichwas shifted with the wing block during its initial movement, started toreturn the expander fingers to their retracted position as shown inFIGURE 13. However, the movement of these fingers is also temporarilyarrested until the bottom surface 147 of the lost motion mechanism abutscam sleeve 169. Thereafter, continued upward movement of pivot arm 68carries cam sleeve 169, pin 81, slide block 94 and wing plate 99upwardly. As pin 81 is shifted upwardly, the expander arms are retractedand slide block 94 is shifted under friction roller 95.

During final upward movement of the pivot arm 68, abutment screw 66engages flange 61 of rocker lever 60 and pivots that rocker leverclockwise in FIGURE 15 to cause the yoke 51 and feed plate 21 to beshifted outwardly in the manner explained below. At this point, the tubeof rubber bands 12 in feed chute 38 drops down wardly under their ownweight onto shelf 47 so that the unit is ready for the next cycle ofoperation.

From the foregoing disclosure of the general principles of the presentinvention and the above detailed description of one preferredembodiment, those skilled in the art will readily contemplate variousmodifications which can be made in the machine without departing fromthe principles of the present invention. By way of example, one slightlymodified rubber band applying machine is shown in a semi-diagrammaticmanner in FIGURES 19 and 20. It is to be understood that themodification as there shown functions in generally the same manner asthe preferred embodiment, except that the modified unit in FIGURES 19and 20 is electrically power actuated.

The control for this unit, as shown in FIGURE 19, is provided by a pushbutton 150. This push button can be manually depressed by the operatorat the beginning of an operating cycle, or alternatively, thisinitiating electrical control can be in the form of a pressure sensitiveswitch, photoelectric cell or the like, which is actuated by articles ona conveyor as they are fed to the band applying machine.

In any event, when switch 150 is closed, a solenoid 151 is energized.This solenoid is connected to an actuating rod 18a and when energized iseffective to pull the actuating rod downwardly. The upper end of theactuating rod is secured to a main pivot arm 68a in the manner describedpreviously. When rod 68a is shifted downwardly, it causes a yoke member51a to be released to advance a feed finger 21a against the rubber bandat the bottom of feed chute 38a in the manner explained above. Since thedetails of this portion of the mechanism are substantially identicalwith the preferred embodiment, it is considered unnecessary to repeatthe details here.

As the feed plate 21a engages the rubber band, it forces the band overfour expander fingers 14a-17a which are disposed in a horizontal rowbeneath the chute in the manner previously described. As the actuatingrod 18a and pivot arm 68a continue to move downwardly, a lost motionmechanism 152 of the type described previously forces a pin 81adownwardly to cause the expander arms to be pivoted outwardly in themanner described above. The linkage for shifting these expander fingersis the same as that described previously and it is not considerednecessary to repeat a detailed description of it at this point.

In the embodiment shown in FIGURES 19 and 20, however, there is nomechanical interconnection between the release mechanism 10a and themain pivot arm 684: as described in the previous embodiment. However,the release mechanism includes two shafts 102a and 103a which 1 1 arespring urged to a position in which the four release fingers 22a-25a aredisposed in a plane as described in connection with the preferredembodiment.

The shafts 102a and 103a are rotatably mounted upon the divider wall 49ain the manner previously described. In the modified embodiment ofFIGURES 19 and 20, inward and outward pivotal movement of the releasefingers is efiected by means of a second solenoid 153. This solenoid ispowered through a circuit including a limit switch 149. While limitswitch 149 has been shown in FIGURE 19 as being actuated upon sufficientmovement of the shaft 68a, it is to be understood that the limit switchcan physically be actuated in any manner whenever the expander fingershave reached a position in which they have substantially stretched therubber band so that it is desired to release the rubber band from thefingers allowing it to snap over the article surrounded by the band.

As is shown in FIGURES 19 and 20, solenoid 153 includes an armature 154which is pushed outwardly from the solenoid whenever the solenoid isenergized. Armature 154 abuts an arm 155. This arm is rigidly secured tothe lower end of shaft 103a as by means of bracket 156 and set screw157. Arm 155 also carries a flange 158 which is pivotally secured to theend of a link 159. Link 159 is in turn pivotally joined to an arm 160.This arm is rigidly connected to the lower end of shaft 102a by means ofa bracket 161 and a set screw 162.

It will be appreciated that when solenoid 153 is energized in responseto movement of expander fingers 14a- 17a, armature 154 is advanced. Itsengagement with arm 155 causes shaft 1030 to be rotated so that releasefingers 23a and 25a are shifted outwardly. At the same time, theinterconnection provided by link 159 causes shaft 102a to be rotated sothat release fingers 22a and 24a are shifted outwardly. These releasefingers force the rubber band from engagement with the expander fingersin the same manner explained above. The device is returned to itsinitial or starting position ready for the next cycle by releasingbutton 150 which deenergizes solenoid 151 and in turn causesdeenergization of solenoid 153.

These and other modifications will suggest themselves to those skilledin the art. For example, an internal band supporting tube can beutilized in place of chute 38. The tube supports the bands relative to ashelf member and fingers with the lowermost band free in the samegeneral manner as chute 38. Also, other forms of power actuators, suchas pneumatic or hydraulic cylinders, can be utilized in place ofsolenoids 151 and 153. Accordingly, we desire to be limited only by thescope of the following claims.

We claim:

1. A method of sequentially feeding elastic bands from a tubularassembly of bands of the type including a plurality of transverse slitsdefining individual bands and an uncut portion retaining the bands inassembled relationship, and method comprising the step of applying aforce against the periphery of the endmost band of said tubularassembly, said force being applied from the outside of said band andbeing directed inwardly toward said uncut strip, whereby said endmostband is caused to rotate about said uncut strip into a plane angulatedwith respect to the original plane of said endmost band.

2. A method of wrapping elastic bands around an article, said methodcomprising the steps of supporting a tubular assembly of bands of thetype including a plurality of transverse slits defining individual bandsand an uncut portion retaining the bands in assembled relationship withat least a portion of the periphery of the endmost band of the tubularassembly exposed, applying a force against the periphery of said endmostband, said force being applied from the outside of said band and beingdirected inwardly toward said uncut strip, whereby said band is causedto rotate about said uncut strip into a plane angulated with respect tothe original plane of said endmost band, engaging the interior of saidband with a plurality of members, restraining the remainder of saidtubular assembly of bands, and shifiting said members in divergent pathsto stretch said band so as to define a large central opening.

3. A method of wrapping elastic bands around an article, said methodcomprising the steps of supporting a tubular assembly of bands of thetype including a plurality of transverse slits defining individual bandsand an uncut portion retaining the bands in assembled relationship 'withat least a portion of the periphery of the endmost band of the tubularassembly exposed, applying a force against the periphery of said endmostband, said force being directed toward said uncut strip, whereby saidband is caused to rotate about said uncut strip, engaging the interiorof said band with a plurality of members, restraining the remainder ofsaid tubular assembly of bands, and shifting said members in divergentpaths to stretch said band so as to define a large central opening,while simultaneously pulling said band free from the tubular assembly.

4. A method of wrapping elastic bands around an article, said methodcomprising the steps of supporting a tubular assembly of bands of thetype including a plurality of transverse slits defining individual bandsand an uncut portion retaining the bands in assembled relationship withat least a portion of the periphery of the endmost band of the tubularassembly exposed, applying a force against the periphery of said endmostband, said force being applied from the outside of the band and beingdirected inwardly toward said uncut strip, whereby said band is causedto rotate about said uncut strip into a plane angulatcd with respect tothe original plane of said endmost band, engaging the interior of saidband with a plurality of members, restraining the remainder of saidtubular assembly of bands, and shifting said members in divergent pathsto stretch said band so as to define a large central opening, insertingan article within the central opening defined by said band, andsubsequently applying a force to said band in a direction transverse toits plane to disengage said band from said members, whereby said bandsnaps around the article.

5. A method of wrapping elastic bands around an article, said methodcomprising the steps of supporting a tubular assembly of bands of thetype including a plurality of transverse slits defining individual bandsand an uncut portion retaining the bands in assembled relationship withat least a portion of the periphery of the end-most band of the tubularassembly exposed, applying a force against the periphery of said endmostband, said force being directed toward said uncut strip, whereby saidband is caused to rotate about said uncut strip, engaging the interiorof said band with a plurality of members, restraining the remainder ofsaid tubular assembly of bands, and shifting said members in divergentpaths to stretch said band so as to define a large central opening,while simultaneously pulling said band free from the tubular assembly,inserting an article within the central opening defined by said band,and subsequently applying a force to said band in a direction transverseto its plane to disengage said band from said members, whereby said bandsnaps around the article.

References Cited UNITED STATES PATENTS 1,886,842 11/1932 Shaw 5332,089,769 8/1937 Strout 53198 2,630,260 3/1953 Tracy et al 53-2912,771,725 11/ 1956 Carter 53292 2,864,212 12/1958 Bruce 53-3 WILLIAM W.DYER, JR., Primary Examiner.

N. ABRAMS, Assistant Examiner.

